Curlew is an easy to use, free Open-Source Multimedia converter for Linux. Curlew written in python and GTK3 and it depends on (ffmpeg/avconv, mencoder). You can choose between a lot of built in presets, preview files before encoding and change advanced encoding settings such as changing the audio/video, bitrate, channels, frequency, aspect ratio, FPS, resolution, enable 2-pass encoding, crop, split (based on duration), change various subtitle based settings, shutdown the PC when done etc.